<s>
The	O
Multi	B-Protocol
Router	I-Protocol
Traffic	I-Protocol
Grapher	I-Protocol
(	O
MRTG	B-Protocol
)	O
is	O
free	B-Application
software	I-Application
for	O
monitoring	O
and	O
measuring	B-Protocol
the	O
traffic	O
load	O
on	O
network	B-Architecture
links	O
.	O
</s>
<s>
It	O
allows	O
the	O
user	O
to	O
see	O
traffic	O
load	O
on	O
a	O
network	B-Architecture
over	O
time	O
in	O
graphical	O
form	O
.	O
</s>
<s>
It	O
was	O
originally	O
developed	O
by	O
Tobias	O
Oetiker	O
and	O
Dave	O
Rand	O
to	O
monitor	O
router	B-Protocol
traffic	O
,	O
but	O
has	O
developed	O
into	O
a	O
tool	O
that	O
can	O
create	O
graphs	O
and	O
statistics	O
for	O
almost	O
anything	O
.	O
</s>
<s>
MRTG	B-Protocol
is	O
written	O
in	O
Perl	B-Language
and	O
can	O
run	O
on	O
Windows	B-Application
,	O
Linux	B-Application
,	O
Unix	B-Application
,	O
Mac	B-Application
OS	I-Application
and	O
NetWare	B-Operating_System
.	O
</s>
<s>
MRTG	B-Protocol
uses	O
the	O
Simple	B-Protocol
Network	I-Protocol
Management	I-Protocol
Protocol	I-Protocol
(	O
SNMP	B-Protocol
)	O
to	O
send	O
requests	O
with	O
two	O
object	O
identifiers	O
(	O
OIDs	O
)	O
to	O
a	O
device	O
.	O
</s>
<s>
The	O
device	O
,	O
which	O
must	O
be	O
SNMP-enabled	O
,	O
will	O
have	O
a	O
management	O
information	O
base	O
(	O
MIB	O
)	O
to	O
look	O
up	O
the	O
OIDs	O
specified	O
.	O
</s>
<s>
After	O
collecting	O
the	O
information	O
it	O
will	O
send	O
back	O
the	O
raw	O
data	O
encapsulated	O
in	O
an	O
SNMP	B-Protocol
protocol	O
.	O
</s>
<s>
MRTG	B-Protocol
records	O
this	O
data	O
in	O
a	O
log	O
on	O
the	O
client	O
along	O
with	O
previously	O
recorded	O
data	O
for	O
the	O
device	O
.	O
</s>
<s>
The	O
software	O
then	O
creates	O
an	O
HTML	B-Language
document	O
from	O
the	O
logs	O
,	O
containing	O
a	O
list	O
of	O
graphs	O
detailing	O
traffic	O
for	O
the	O
selected	O
devices	O
in	O
the	O
server	O
.	O
</s>
<s>
Alternatively	O
,	O
MRTG	B-Protocol
can	O
be	O
configured	O
to	O
run	O
a	O
script	O
or	O
command	O
,	O
and	O
parse	O
its	O
output	O
for	O
counter	O
values	O
.	O
</s>
<s>
The	O
MRTG	B-Protocol
website	O
contains	O
a	O
large	O
library	O
of	O
external	O
scripts	O
to	O
enable	O
monitoring	O
of	O
SQL	O
database	O
statistics	O
,	O
firewall	O
rules	O
,	O
CPU	O
fan	O
RPMs	O
,	O
or	O
virtually	O
any	O
integer-value	O
data	O
.	O
</s>
<s>
Gets	O
its	O
data	O
via	O
an	O
SNMP	B-Protocol
agent	O
,	O
or	O
through	O
the	O
output	O
of	O
a	O
command	O
line	O
.	O
</s>
<s>
Creates	O
an	O
HTML	B-Language
page	O
per	O
target	O
that	O
features	O
four	O
graphs	O
(	O
GIF	O
or	O
PNG	O
images	O
)	O
.	O
</s>
<s>
Adds	O
calculated	O
Max	O
,	O
Average	O
and	O
Current	O
values	O
for	O
both	O
I	O
and	O
O	O
to	O
the	O
target	O
's	O
HTML	B-Language
page	O
.	O
</s>
